Treatise Upon the Genesis and Development of the Dental Follicles to the Epoch of the Eruption of the Teeth. [Volume: 2, Issue: 1, August, 1860, pp. 3-10]

4

THE DENTAL COSMOS.

The second chapter will be devoted to the study of the genesis and
constitution of the follicle, considered from the moment of the appearance of the bulb, which is always first produced, until the commencement
of the production of the tooth-that is to say, to the birth of the first
hollow crown or cap of the dentine.
The third chapter will treat of the manner of origin and development
of the constituent parts of the tooth-ivory, enamel, and dentine; and
also of the structure of the formative organs of these parts.
Finally, in the fourth and last chapter, we will describe, in discussing
them, the processes that have been followed in order to ascertain the
anatomical and physiological particularities mentioned in the first three
chapters.
The observation of the facts upon which this treatise rests is, if not
easy, at least fruitful in results of great accuracy. The transparency of
the parts is favorable to observation, and permits great distinctness in following the outlines which limit each of the organs under consideration;
these outlines are at first diffuse, then more and more distinct. When an isolated preparation is studied for the first time, it is found very perplexing
to give an exact interpretation of such and such of these outlines, or of
the nature of the organ limited by them; but as the same preparation
may unite in itself a series of juxtaposed follicles, the constancy and
regularity of the relations which affect the organs that constitute them
give a certain preciseness to the decision of the nature of the objects.
Finally, this decision becomes at the same time easy and accurate, when
the observation is made on a series of pieces from the same subject at
different ages, or on pieces belonging to distinct species. The comparison of these organs at their different periods in the same animal, and the
comparison of the follicles in different species, always show similar anatomic relations, (excepting some secondary differences in form and size;)
this leaves no place for doubt relative to the nature and office of each of
the constituent parts of the follicular apparatus.
It is astonishing that uncertainty has existed so long in regard to the
determination of the phenomena of the genesis and evolution of the teeth.
This is, without doubt, the result of the constant neglect of collecting and
observing a series of preparations, corresponding to the successive phases
of the same phenomenon in different animal species.
When the constituent parts of the follicle are completely collected and
grouped in their reciprocal relations, each follicle soon becomes too voluminous to be observed in its entirety by the aid of transmitted light. By
the time that the various organs of the follicles are individually more
developed, and more easy to dissect, the advantages of their transparency and the simultaneous observation of all the tissues in process of
evolution are lost on account of their size. But in compensation for this,
the anatomic nature of each organ can be determined at this time, and